Answer :
I don't quite know what you wrote but if it's 2 bows for every shirt the answer will be 100. If it is says 2 bows for every 20 shirts then the answer will be 5 bows
He has 5 bows.
Add one set of 2bows and 20 shirts and add them untill you reach 40.
(4 bows, 40 shirts)
Then, to make 50 you add 10 so divide 20 by 2 and then 2/2 and you get 1 bow and 10 shirts.
Add all that together and you get 5 bows and 50 shirts.